Apparatus and method for precision metering and deposit of viscous materials



Sept. 13, 1966 Q RQESER 3,272,393

APPARATUS AND METHOD FOR PRECISION METERING AND DEPOSIT OF VISCOUSMATERIALS Filed D60. 13, 1963 fave-722 01 IEXz @fiawer United StatesPatent APPARATUS AND PLTET HQD FUR lliiEClSlON METERING AND DEPGSET URVlSCQUS MATE- RIALS John E). Rocser, 8611 Lincoln Ave, Morton Grove,iill.

Filed Dec. 13, 1963, Set. No. 330,484 9 Claims. (Cl. 222-179) Thisinvention relates to an injector for precision metering and deposit ofvariable quantities of a viscous material such as epoxy resin systems,potting compounds, adhesives and similar materials.

The new epoxy resins are widely used for potting small electroniccomponents and for sealing terminal connections of switches, microphonesand similar electronic components. The epoxy resins fall into two broadcategories, heat activated one part systems or two part systems thatstart hardening when mixed.

The two part system finds more general use as it avoids the applicationof heat to the component being processed and because it is moreconvenient to handle. One particular problem in the application of thetwo part system arises from the fact that once mixed, the systemprogressively becomes highly viscous and tacky and ultimately hardens.Working life may be from a few minutes to one hour. When the materialhardens it sticks tenaciously to the mixing and applicator equipment andcleanup is a major problem.

There are presently available, commercial devices utilizing hand heldguns having discharge nozzles equipped with finger manipulable valves.These devices have many parts associated with the valving action whichmust be cleaned. Moreover, the valving motion encumbers precisionmaneuver of the gun and disturbs the placement of the material. Inaddition, the discharge passage is relatively long to accommodate thevalving mechanism and this results in a shortened pot life for thecharge.

For these reasons, there are many in this art who still use toothpicksor hypodermic syringes for applying small amounts of epoxy. Thus, thereexists a genuine need for an injector for handling the deposit ofviscous materials such as epoxy resin systems.

The principal object of the invention is the provision of an injectorfor precision metering and deposit of viscous materials.

Another object is the provision of such an injector having facilitiescontrollable to vary the quantity of material to be discharged.

A more specific object of the invention is the provision of a method andan apparatus employing a hand maneuverable storage and dischargecartridge equipped with a flexible air pressure supply controlled by aproportional treadle movement to provide a full range of variablecontrol without disturbing the cartridge placement.

A further object of the invention includes the provision of injectorapparatus characterized by a reuseable cartridge having a cylindricalreservoir and provided with a full size air inlet opening at one end anda short valveless discharge nozzle at the other end.

Still another object is the provision of an injector apparatuscharacterized by a cartridge having a reservoir for receviing a chargeof viscous material, a short valveless discharge nozzle at one end and aflexible air supply line at the other end to apply air under pressuredirectly against the charge.

Other and further objects of the present invention will be apparent fromthe following description and claims, and are illustrated in theaccompanying drawings which show structure embodying preferred featuresof the present invention and the principles thereof, and what is now3,272,393 Patented Sept. 13, i966 considered to be the best mode inwhich to apply these principles.

In the accompanying drawings:

FIG. 1 is a diagrammatic side view partly in section illustrating apreferred injector apparatus constructed in accordance with thisinvention;

FIG. 2 is a sectional view through a cartridge and showing aself-contained charge therein;

FIG. 3 is a sectional view through a cartridge that is equipped with afloating piston; and

FIG. 4 is a sectional view through a dispenser cartridge in the form ofa can equipped with an air inlet line and liquid discharge line.

Referring now to the drawings, and particularly to FIG. 1, a completeinjector assembly is illustrated for the precision metering and depositof variable quantities of viscous material such as epoxy resin systems,potting compounds and adhesives. The assembly includes a pressureregulating valve unit 10 of basically conventional form which is hereshown mounted on a bench top T. The valve 10 has a valve casing 11provided with an air inlet passage HI, an air outlet chamber 11C and anair vent chamber 11V. Air flow from the inlet passage 111 to the outletchamber 11C is regulated by a valve head 12 that is biased to closedposition by a spring 13 and that includes a stem 12S projecting into theupper end of the vent chamber 11V. A flexible diaphragm 14 divides thevent chamber and includes a central disc 12D provided with a port 121which is normally closed by the valve stem 128.

The valve unit It has its lower end projecting through the bench top Tand equipped with a vertically slidable plunger 15 which transmits forceto the diaphragm 14D by means of a load spring 16 housed within the ventchamber 11V. The plunger 15 constitutes an externally accessibleactuator that is shiftable for applying a proportional force to thediaphragm to elevate the valve head 12 and open a flow passage throughthe valve from inlet 111 to outlet 111. As is conventional, theresultant pressure acting at the outlet HP is variable in accordancewith the position of the valve head 12.

Finally, the valve has an internal vent passage 17 establishingcommunication between the outlet chamber 11C and the upper region of thevent chamber 11V. In the event the valve has been set to some selectedvalve opening position and air under cor-responding pressure is beingsupplied to and through the outlet chamber, an abrupt closure of thevalve head 12 by release of the plunger 15 results in an excess airpressure on the downstream side of the valve. An important feature ofthis valve is that this excess of pressure is dumped rapidly tofacilitate instant shut-off. The dumped air follows a path that extendsfrom the outlet chamber through the internal vent passage 17, throughthe port lZP in the diaphragm disc 12D which is now open by virtue ofthe existence of the excess downstream air pressure, and finally throughan external vent passage 18 that leads from the vent chamber 110.

In the injector arrangement constructed in accordance with thisinvention, the valve unit 10 has its air inlet passage 11I equipped witha feed line 19 connected to a source of air under pressure, its airoutlet passage 11C connected to an air supply line 20, and its pressureregulating proportional plunger 15 connected to be controlled by atreadle actuated mechanism for regulating the supply of air to thedesired pressure.

As illustrated herein, the treadle actuated mechanism includes a lever21 pivotally mounted to the bench. One end of the lever 21 underlies theplunger 15' and the other end is connected to a cable 22 which extendsupwardly from a treadle 23 that may be pivotally mounted on a suitablefloor mounted base 24 to enable the operator to 1?) apply proportionalcontrol by foot action on the treadle and position the plunger to selectany desired air pressure. By this arrangement, air turn-on and airshutofi. and all graduations in the pressure selection are effected bytreadle control of the valve unit It and the operators hands are free tohandle the injector head or cartridge 25.

In the preferred form of the invention the injector head 25 is in theform of a re-usable cartridge defining a reservoir R for receiving acharge C of viscous material and having an endwise directed orificedischarge passage P at one end and a cup shaped cap as removably mountedin air tight sealed relation around the other end. The air supply line2t is in the form of an elongated flexible air supply tube having oneend connected to the air outlet chamber 11C of the valve unit and havingthe other end connected in sealed relation to the cartridge cap 25 tocommunicate with reservoir R through a passage MP in the cap.

The cartridge is of a size to facilitate grasping and maneuver by onehand and typical cartridges may be of the following sizes: a /2 inchdiameter cartridge may have a reservoir volume of /3 cubic inch and anorifice diameter of .032 inch. A 1% inch diameter cartridge may have areservoir volume of five cubic inches and an orifice diameter of .062inch.

In one preferred embodiment of the invention as illustrated in FIG. 1,the cartridge 25 is of one-piece construction and includes a housingportion 25H providing a cylindrical reservoir R having a full sizedinlet opening across the air entry end thereof, and a valveless nozzleportion ZSN rigidly carried on the housing portion 25H at its oppositeend and providing an endwise directed orifice discharge passage for thereservoir. The cartridge reservoir is filled through its large open endwith a charge C of viscous material such as a two part epoxy resin sys--tem and the cartridge is then hand-guided to locate its nozzle exit at aposition for depositing a controllable quantity of the viscous material.For this purpose the operators foot applies proportional control throughthe treadle 23 and the motion transmitting cable 22 and lever 21 to openthe valve unit appropriately for applying air at the required pressuredirectly to the charge of viscous material which is then extruded fromthe cartridge at an appropriate rate.

As soon as the operators foot returns the treadle 23 to initial positionand an external return spring 27 restores lever 21 to enable the plungerto be returned to the air-off position, an excess of pressure existsdownstream of the valve 10. This excess downstream pressure deflects thediaphragm J14 downwardly to open the vent port 12F and permit dumping ofthe downstream air. This action facilitates instant shut-oil andeliminates drippage from the nozzle. During the actual depositing actionthe flow of the viscous material may easily be varied in accordance withthe requirements of the particular operation, all of this beingaccomplished by proportional treadle movement and thus in no wayinterfering with the precision location and hand guidance of thecartridge head.

There is particular advantage in the fact that the air under pressure isapplied directly to the charge C of viscous material. This gives fastresponse and reduces the effort required in the case of highly viscousresins. More importantly, however, the shut-off response is much quickerthan would be the case where the pressure is applied through a piston 28mounted in floating relation in the reservoir as illustrated in FIG. 3.In the latter instance, friction is always acting between the piston andthe cartridge walls so that when air pressure behind the piston isreduced, friction causes the piston 28 to remain at its advancedposition wherein it pushes against the charge of material. In addition,it is inevitable that air bubbles will exist forwardly of the piston 28and being under a high degree of compression, they will produce forcesthat con tinue to push out resin, even after air shut-off. The techniqueof using air under pressure to contact directly against the charge isuseful for injection of any type material that will slump sufiicientlyto prevent air from tunneling through to the nozzle.

Other features in the cartridge arrangement reside in the fact that thenozzle ZSN is valveless, permitting the orifice passage to be of minimumlength. Moreover, the reservoir R is immediately adjacent the nozzle sothat the material has a short overall travel path when exiting from thecartridge, thus facilitating extrusion of highly viscous materials.

Another important practical aspect of the invention is that the viscousmaterial touches only a single part--the cartridge 25 and it has aconfiguration that facilitates cleanup. Thus, the cylindrical reservoirR having a full width opening at the air inlet end, enables a drill tobe inserted for cleanout of the reservoir after the resin has hardenedtherein. Another drill may be inserted through the nozzle end tocomplete the cleaning operation and enable re-use of the cartridge.Thus, the invention permits the use of expensive precision nozzles ascleanup is no longer a problem. It should be noted that the inventionalso contemplates that disposable cartridges 25 might be employedinstead of the re-usable cartridges described previously.

Another variation of the device is illustrated in FIG. 2 wherein thecartridge 25 is shown equipped with a charge C which includes a plasticcarrier bag 29 having a nozzle 29N press fit into the cartridge. The bagis useful in facilitating initial insertion of the charge into thereservoir and it is collapsible progressively with expulsion of thecharge from the reservoir. This FIG. 2 arrangement has the advantage ofpreventing the resin from contacting the housing portion 25H of thecartridge.

While the floating piston arrangement as indicated previously hascertain disadvantages, the invention does contemplate the use of such afloating piston 28 for certain applications and such an arrangement isshown in FIG. 3.

Finally, another cartridge arrangement is illustrated in FIG. 4 whereina closed one quart 29 can serves as the cartridge and is equipped with aflexible air supply line 26 shown entering at the top and a liquiddelivery tube 3%) shown extending from a location adjacent the bottom ofthe can through the top to act as the injector nozzle. This can-typecartridge is normally contemplated for use with a one part resin.

While proportional air pressure control is contemplated for precisiondepositing operations, it should be apparent that the injector in manyinstances may be used with a direct three-way air valve to provide asimple on-ofi arrangement for controlling the supply of air to thecartridge. Even in simple on-off arrangements of this type, there isimportant advantage in the fact that the cartridge is freely handmaneuverable and the on-off control is effected by the treadle 23 andthus in no way disturbs the guidance of the cartridge.

Thus, while preferred constructional features of the invention areembodied in the structure illustrated herein, it is to be understoodthat changes and variations may be made by those skilled in the artwithout departing from the spirit and scope of the appending claims.

What is claimed is:

1. In an injector for one-handed precision metering and deposit ofvariable quantities of viscous material, the combination with an airpressure valve unit having an air inlet connected to a source of airunder pressure, an outlet, and means for controlling flow of air underpressure from said air inlet to said air outlet; of a cartridge of asize and shape suitable for engagement and maneuver by hand andincluding a housing portion providing a reservoir for receiving a chargeof viscous material and a valveless nozzle portion rigidly carried onsaid housing portion and providing an orifice discharge passage! f0!said reservoir, means including an elongated flexible air supply tubehaving one end connected to said air outlet and having the other endconnected in sealed relation to said housing portion for supplying airunder pressure into a region of said reservoir remote from said nozzleportion to eflect application of pressure on said charge, and treadleactuated mechanism connected to said controlling means for controllingthe supply of air under pressure to said tube.

2. In an injector for one-handed precision metering and deposit ofvariable quantities of viscous material, the combination with an airpressure valve unit having an air inlet connected to a source of airunder pressure, an outlet, means for controlling flow of air underpressure from said air inlet to said air outlet and means for dumpingdownstream air when downstream air pressure is in excess of thatcorresponding to the value determined by said controlling means; of acartridge of a size and shape suitable for engagement and maneuver byhand and including a housing portion providing a reservoir for receivinga charge of viscous material and a valveless nozzle portion rigidlycarried on said housing portion and providing an orifice dischargepassage for said reservoir, means including an elongated flexible airsupply tube having one end connected to said air outlet and having theother end connected in sealed relation to said housing portion forsupplying air under pressure into a region of said reservoir remote fromsaid nozzle portion to eifect application of pressure on said charge,and treadle actuated mechanism connected to said controlling means forcontrolling the supply of air under pressure to said tube.

3. An injector for one-handed precision metering and deposit of variablequantities of viscous material and comprising a cartridge of a size andshape suitable for engagement and maneuver by hand and including a housing portion providing a reservoir for receiving a charge of viscousmaterial and a valveless nozzle portion rigidly carried on said housingportion and providing an orifice discharge passage for said reservoir,means including an elongated flexible air supply tube connected insealed relation to said housing portion for supplying air under pressureinto a region of said reservoir remote from said nozzle portion tocontact directly against said charge, and a treadle actuated mechanismfor controlling the supply of air under pressure to said tube.

4. In an injector for one-handed precision metering and deposit ofvariable quantities of viscous material, the combination with an airpressure valve unit having an air inlet connected to a source of airunder pressure, an outlet, and means for controlling flow of air underpressure from said air inlet to said air outlet; of a hand maneuverabledispensing unit including means forming a reservoir for receiving acharge of viscous material, and a valveless nozzle tube providing anorifice discharge passage having one end in direct communication in thecharge contained in said reservoir and having a discharge end projectingfrom said reservoir, means including an elongated flexible air supplytube having one end connected to said air outlet and having the otherend connected in air tight sealed relation to communicate directly withsaid reservoir at a region thereof to effect application of pressure onsaid charge for forcing said liquid out said nozzle tube, and treadleactuated mechanism connected to said controlling unit for controllingthe supply of air under pressure to said tube.

5. An injector for one-handled precision metering and deposit ofvariable quantities of viscous material and comprising a reversiblecartridge of a size and shape suitable for engagement and maneuver byhand and including a housing portion providing a cylindrical reservoirfor receiving a charge of viscous material and having a full size inletopening across one of said reservoir and a valveless nozzle portionrigidly carried on said housing portion at the other end of saidreservoir and providing an endwise directed cylindrical orificedischarge passage for said reservoir, a cup shaped cap removably mountedin air tight sealed relation around one end of said housing portion tospan said inlet opening and having a central through passage, anelongated flexible air supply tube having one end connected to said capto supply air through said passage to contact directly with the materialin said reservoir, an air pressure regulator connected to the other endof said tube for supplying air under pressure to said reservoir andincluding means for dumping air when downstream air pressure is inexcess of that corresponding to the regulator setting, and aproportional treadle actuated mechanism for varying the pressure settingof said regulator.

6. An injector for one-handed precision metering and deposit of variablequantities of viscous material and comprising a reusable cartridge of asize and shape suitable for engagement and maneuver by hand andincluding a housing portion providing a cylindrical reservoir forreceiving a charge of viscous material and having a full size inletopening across one end of said reservoir and a valveless nozzle portionrigidly carried on said housing portion at the other end of saidreservoir and providing an endwise directed cylindrical orificedischarge passage for said reservoir, a cup-shaped cap removably mountedin air tight sealed relation around one end of said housing portion tospan said inlet opening and having a central through passage, anelongated flexible air supply tube having one end connected to said capto supply air through said passage to contact directly with the materialin said reservoir, an air pressure regulator having an air inletconnected to a source of air under pressure, an air outlet connected tothe other end of said tube, valve means for regulating flow of air fromsaid air inlet to said air outlet, an externally engageable actuatorshiftable for applying a proportional force to open said valve means,and means for dumping downstream air when downstream air pressure is inexcess of that corresponding to the current position of said actuator, atreadle mounted for reversible movement, and motion transmittingmechanism connected between said treadle and said actuator for effectingvariation in air pressure applied to said reservoir in proportion tomovement of said treadle.

7. An arrangement in accordance with claim 1 and wherein said cartridgehas a floating piston in said reservoir and having one face exposed toair under pressure supplied through said tube and an opposite faceexposed to engage against the charge in said reservoir.

8. An arrangement in accordance with claim 1 and wherein said chargeincludes a collapsible bag that receives the liquid and that has saidnozzle portion integral with said bag and projecting in press fitrelation through said housing portion.

9. An arrangement in accordance with claim 4 wherein said reservoirforming means comprises a closed can, and said nozzle tube has one endwithin the can at a lower region thereof and has an opposite endextending outwardly of the can to deliver the charge.

References Cited by the Examiner UNITED STATES PATENTS 160,936 3/1875Meyer 222--179 166,567 8/1875 Steele 137505.11 1,390,011 9/1921 Bliven222389 1,465,620 8/1923 Anderson 222-94 X 1,520,745 12/1924 Bowden222394 X 1,888,310 11/1932 Davis 2S1295 X 2,615,598 10/1952 Watkins eta1. 222-397 2,665,825 1/ 1954 Poitras et al. 222-179 X 2,709,542 5/1955Eller et a1. 222-394 X 3,124,276 3/ 1964 Grout 222394 X ROBERT B.REEVES, Primary Examiner.

LOUIS J. DEMBO, EVON C. BLUNK, Examiners.

F. R. HANDREN, H. S. LANE, Assistant Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,272,393 September 13, 1966 John O. Roeser It is hereby certified thaterror appears in the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Column 5, line 65, for "one-handled" read one-handed line 71, after"one" insert end Signed and sealed this 29th day of August 1967.

(SEAL) Attest:

ERNEST W. SWIDEB Attesting Officer EDWARD J. BRENNER Commissioner ofPatents

1. IN AN INJECTOR FOR ONE-HAND PRECISION METERING AND DEPOSIT OFVARIABLE QUANTITIES OF VISCOUS MATERIAL, THE COMBINATION WITH AN AIRPRESSURE VALVE UNIT HAVING AN AIR INLET CONNECTED TO A SOURCE OF AIRUNDER PRESSURE, AN OUTLET, AND MEANS FOR CONTROLLING FLOW OF AIR UNDERPRESSURE FROM SAID AIR INLET TO SAID AIR OUTLET; OF A CARTRIDGE OF ASIZE AND SHAPE SUITABLE FOR ENGAGEMENT AND MANEUVER BY HAND ANDINCLUDING A HOUSING PORTION PROVIDING A RESERVOIR FOR RECEIVING A CHARGEOF VISCOUS MATERIAL AND A VALVELESS NOZZLE PORTION RIGIDLY CARRIED ONSAID HOUSING PORTION AND PROVIDING AN ORIFICE DISCHARGE PASSAGE FOR SAIDRESERVOIR, MEANS INCLUDING AN ELONGATED FLEXIBLE AIR SUPPLY TUBE HAVINGONE END CONNECTED IN SEALED AIR OUTLET AND HAVING THE OTHER ENDCONNECTED IN SEALED RELATION TO SAID HOUSING PORTION FOR SUPPLYING AIRUNDER PRESSURE INTO A REGION OF SAID RESERVOIR REMOTE FROM SAID NOZZLEPORTION TO EFFECT APPLICATION OF PRESSURE ON SAID CHARGE, AND TREADLEACTUATED MECHANISM CONNECTED TO SAID CONTROLLING MEANS FOR CONTROLLINGTHE SUPPLY OF AIR UNDER PRESSURE TO SAID TUBE.